This program for controlling iTunes from just about any application.

iMote Description

iMote is a simple, elegant, and lightweight program for controlling iTunes from just about any application. Play/pause, change tracks, select playlists, adjust volume, rate tracks, and more using fully customizable hot-keys or a Universal menu bar item. iMote includes a beautiful iPod-esque floating window, indicating current track information, and Growl support if you want an even more streamlined experience with your other Growl-enabled applications. Written using Cocoa, iMote is lean and mean, consuming minimal system memory and CPU time. iMote is the original iTunes controller.